Questions about cod worms

Before I introduce you to more fish parasites, let me answer all the questions I got about cod worms.

Q: How do you remove cod worms? Do you have to use a match like you would for a tick to ensure that no part of it remains in the fish?
A: No match. They’re only potentially harmful if you ingest them live. I just pull them out with my fingers (wearing gloves since I am a squeamish wimp), but as Stephanie suggested, tweezers might be an easier way to remove the worms.

Q: What would happen if a cod worm were to survive in your stomach?
A: Nothing life threatening or permanently damaging will happen, but you are likely to experience a terrible stomach ache, nausea, and vomiting. If you experience these symptoms after eating raw fish, it’s important to tell the doctor which species of fish you’ve recently eaten raw, cured, or salted. In US, the instances of parasite infections (anisakiasis) are so rare that they are often misdiagnosed as appendicitis, ulcer, or some other gastrointestinal disease. If diagnosed correctly, anisakiasis can pass all by itself (when the parasites die), or be treated with a drug called albendazole. In rare cases, surgical intervention might be necessary.

Q: I found a worm in tuna at a sushi restaurant. What do I do?
A: What you probably found wasn’t a worm, but rather a strand of fat or sinuous tissue. Worms in large tuna (such as yellowfin, bluefin, and big-eye) are exceedingly rare. Even if what you found was really a worm, don’t worry. All restaurants in the U.S. are required to freeze fish before it is served raw. The freezing process will kill any worms that aren’t removed via inspection. However, if that “strand of fat” was really moving and wriggling on its own, then it’s not a strand of fat---it’s a live worm. One possibility is that the sushi restaurant served you a small tuna (such as Bonito), which is susceptible to worms. Most fresh fish sold as “tuna” is large tuna. As an extra precaution, you can ask your fishmonger or sushi restaurant the tuna species. If it’s yellowfin/ahi, bluefin or big-eye, then you shouldn’t need to worry about worms/parasites.

Q: Is eating fresh, raw yellowfin, bluefin or big-eye tuna dangerous?
A: No---at least, not as far as parasites are concerned. Your chances of dying in a car accident driving to/from your fish market to buy a loin of tuna are much higher than your chances of getting sick from a parasite from the tuna you buy. Parasites are virtually nonexistent in tuna meat sold fresh in the U.S. A more important concern is bacteria. Fish meat is more susceptible to bacteria growth than other types of meat (e.g. cow, pig, duck). So, it’s important that you buy from a reputable source and keep your tuna on ice at all time before serving (I bring a cooler with ice-packs with me to the market).